Roof Insulation vs. Condensation

[finn1]

Another Pte for firing out the purlins to create an air gap, then adding soffit and ridge vents.

 

[Welshman]

The inside face of the insulation will be 70 degrees and in winter the outside face will be 30 degrees. There is a 40 degree temperature drop through the insulation. If the dew point is at 50 degrees, then the dew point will occur in the center of the insulation. This is acceptable because the closed cell foam will not absorb any moisture.

Yes, spray foam the gaps after installation.

So you have a pole building with wood sheathing for the roof and walls? If so, that's ok because won't change the assembly.

Thank you for that.